How do brain cancer cells metastasize?

In recent years, brain cancer has gradually risen again, and brain cancer screening has been elevated to a position that needs attention. Humans are afraid of death, but when it is really irreversible, they are powerless. There are countless people who have died from cancer, and brain cancer is one of the killers. People who are usually very careful and cautious will find symptoms in the early stage, but some people do not have any symptoms in the early stage, so it is best to check regularly. Clinically, it is found that most brain cancer patients have reached the middle and late stages when they show obvious symptoms. Here, we remind the majority of friends who are related to brain cancer to pay attention.

Metastasis of brain cancer

There is no obvious correlation between the malignancy of brain tumors and metastasis. Brain tumor metastasis is mainly intracranial, while cranial metastasis is less common.

1. Intracranial metastasis

Also known as implantation metastasis, the conditions for this type of metastasis are that the tumor is rich in tumor cells and less in stroma, so the tumor cells are easy to fall off; or because the tumor tissue is exposed to the cerebrospinal fluid pathway, the shed cells are carried to a distant place or deposited on the ventricular wall. Tumors that meet the above conditions include medulloblastomas in the fourth ventricle and ependymoblastomas on the ventricular wall. In addition, choroid plexus papilloma and other gliomas that protrude into the ventricles have also been reported. Sometimes the tumor is not close to the ventricles or subarachnoid space, but surgery, especially tumor biopsy or partial resection, can cause tumor cells to fall off and spread in the subarachnoid space, increasing the chance of this type of metastasis. Most metastatic nodules are located in the various cisterns of the skull base and the subarachnoid space of the spinal cord.

2. Extracranial metastasis

It is generally rare. The main reason is that the body's circulatory system has a strong ability to reject free brain tumor cells, and at the same time, the brain lacks lymphatic channels for metastasis. In addition, most intracranial tumors require a higher growth environment and conditions. After metastasis to the extracranial area, they often need a longer incubation period to develop due to the inability to adapt to the environment. The survival of patients with intracranial tumors is short. They may die due to increased intracranial pressure or endangerment of the vital center before the metastasis is discovered. However, these conditions that hinder extracranial metastasis can disappear with the continuous progress of treatment. First of all, after the intracranial tumor is surgically removed and treated comprehensively, the patient's life is prolonged; in addition, the chance of contacting the dura mater, scalp and extracranial soft tissue during surgery is greatly increased, and sometimes even tumor cells directly enter the open lymphatic vessels and vascular cavities, which increases the chance of postoperative tumor recurrence on the dura mater and extracranial tissues, and the lymphatic channels in these tissues provide a pathway for the tumor to metastasize to farther distances. Most of the extracranial metastases reported in the literature occur after surgery, and some people even believe that surgery is a necessary condition for extracranial metastasis of brain tumors. But there are also spontaneous metastases, especially when the tumor is highly invasive and can penetrate the dura mater and invade extracranial tissues. Literature has reported that tumors that can metastasize to the extracranial area include gliomas, meningiomas, primary sarcomas, etc. Among gliomas, multiforme glioblastomas are the most common, accounting for 1/3, followed by medulloblastomas, ependymomas, oligodendrogliomas, astrocytomas, and undifferentiated gliomas. Meningioma metastasis is most common in epithelial cell type hemangioblastomas with rich blood supply. Metastatic lesions can occur almost everywhere in the body, but the most common sites are the lungs and pleura, accounting for 33%; cervical and mediastinal lymph nodes account for 22%; liver 14%, spine and bone marrow system account for 9%, kidneys account for 6%, and other rare sites include heart, ovaries, uterus, bladder, parotid glands, thyroid, thymus, adrenal glands, stomach, colon, scalp, peritoneum, etc.

The above is a brief introduction to "How do brain cancer cells metastasize?" For people who are related to the pathogenic factors of brain cancer, it is recommended to take preventive measures for brain cancer and receive specific treatment according to the doctor's instructions. I hope that patients can recover soon! If you have other questions about brain cancer, please consult our experts online or call for consultation.

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